1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device including bonding onto a bonding target, and to bonding apparatuses.
2. Description of the Related Art
Wire-bonding generally includes a first bonding step in which an initial ball is formed at a tip end of a bonding wire to be fed out of a capillary and is applied by ultrasonic vibration while in pressure contact with a pad surface of a semiconductor device to bond the initial ball to the pad surface. In a second bonding step thereafter, the bonding wire is fed out of the capillary to form a wire loop, and the bonding wire and the capillary are brought into pressure contact with a lead surface of a substrate to bond the bonding wire to the lead surface and then cut the bonding wire.
However, the substrate may be in an unstable state such as wobbling on a bonding stage, suffering from a problem in that the initial ball may not be bonded reliably to the pad surface in the first bonding step and/or the bonding wire may not be cut in the second bonding step.
Hence, in the related art described in Japanese Patent No. 2530224, an XY table with a capillary mounted thereon undergoes a scrubbing motion to be moved in the XY direction during bonding, so that an initial ball is rubbed on and bonded reliably to a pad surface.
However, in the related art described in Japanese Patent No. 2530224, the initial ball may be deformed and expanded during the scrubbing motion, while bonded to the pad surface in the first bonding step, to have an enlarged deformation area. For this reason, the related art described in Japanese Patent No. 2530224 suffers from a problem in that accurate bonding onto a small pad surface is difficult and the pad pitch serving as the distance between adjacent pad surfaces, cannot be reduced.
It is noted that the capability of cutting the bonding wire in the second bonding step is still left unsolved even with the related art described in Japanese Patent No. 2530224.